1. Field of the Invention
The present invention relates to the field of minimally invasive surgical medical devices and medical procedures. More specifically, the invention relates to devices and methods used for transcervical gynecological procedures.
2. Discussion of Related Art
Female contraception and/or sterilization may be affected by transcervically introducing an object (e.g. a coil) into a fallopian tube to inhibit conception. Devices, systems and methods for such a contraceptive approach have been described in various patents and patent applications assigned to the present assignee. For example, PCT Patent Application No. PCT/US98/20031 published as WO 99/15116 and U.S. Pat. No. 6,526,979 and U.S. Pat No. 6,634,361, and is hereby incorporated herein by reference in its entirety, describe devices that are transcervically inserted into an ostium of a fallopian tube and mechanically anchored within the fallopian tube. The devices described in these patents and patent applications may promote a tissue in-growth around and within the inserted device, which may be referred to as an implant or an insert. One example of such devices is the device known as “Essure” from Conceptus, Inc. of Mountain View, Calif. This tissue in-growth tends to provide long-term contraception and/or permanent sterilization without the need for surgical procedures.
The device used to insert the contraceptive implant into the fallopian tube may be an intrafallopian contraceptive delivery device such as the one illustrated in FIG. 1a. 
FIG. 1a illustrates a device similar to the Essure device. The intrafallopian contraceptive delivery device 101 of FIG. 1a is typically formed of a control device, such as a handle 102, a delivery catheter system 103, and a guidewire 104 onto which is held the contraceptive implant to be placed within the fallopian tube. The delivery catheter system 103 contains the guidewire 104, a release catheter (not shown) and the contraceptive implant and the guidewire 104 within the release catheter. The delivery catheter system 103 is transcervically positioned into the uterus and the fallopian tubes via a hysteroscope, such as hysteroscope 100 illustrated in FIG. 1b. The delivery catheter system 103 and guidewire 104 enter the hysteroscope 100 through the working channel 110 of the hysteroscope 100. A distention valve 120 is typically positioned at the tip of the working channel 110. The distention valve 120 seals the entrance of the working channel 110 to prevent a distention fluid, such as saline, to flow out of the hysteroscope 100 as a device, such as the delivery catheter system 103 and guidewire 104 of the intrafallopian contraceptive delivery device 101, is introduced into the working channel 110. The opening 130 into the distention valve 120 is designed to prevent the leakage of any fluid out of the hysteroscope 100 and therefore has the smallest opening possible to allow a very tight fit between the device and the valve opening. To prevent damaging the tip 105 of the guidewire 104 or the contraceptive implant to be inserted into the fallopian tube, the guidewire 104 and delivery catheter system 103 are introduced into the distention valve 120 through an introducer sheath 140. The introducer sheath 140 is formed of a soft flexible material such as plastic or Teflon and has a slit 145 to aid in grasping and in the removal of the introducer sheath 140. The introducer sheath 140 must therefore be inserted into the opening 130 of the distention valve 120 while on a stiff mandrel 150 as illustrated in FIG. 1b. Once the mandrel 150 are placed within the distention valve 120 and the channel 110 to the desired depth the mandrel 150 is removed, leaving the introducer sheath 140 within the working channel 110 and the distention valve 120 as illustrated in FIG. 1c. After placing the introducer sheath 140 into the distention valve 120 the tip 105 of the guidewire 104 and the delivery catheter system 103 may be inserted into the introducer sheath 140 and introduced into the distention valve 120 and the working channel 110 as illustrated in FIG. 1d. The introducer sheath 140 may then be removed. The distention valve 120 may have a tight opening that places pressure on the delivery catheter and causes friction. This friction may make the positioning of the insert within the fallopian tubes difficult. Friction may be created even if the introducer sheath 140 is left within the opening 130 of the distention valve 120. The distention valve 120 prevents fluid leakage from the working channel 110. If an introducer sheath 140 is inserted through the distention valve 120, fluid can spray out of the valve and onto the physician or physician's assistant. The amount of fluid spray-back can be significant depending on the fluid pressure used during the procedure.
Once a physician has positioned the delivery catheter system 103 and the guidewire 104 at a position within the fallopian tube where the contraceptive implant may be deposited, it may be awkward and difficult for the physician to maintain the position and may require the physician to use an assistant to aid in the proper stabilization of the system relative to the hysteroscope.
The contraceptive implant devices in the above references require disengaging from a delivery catheter by using an axial torque. In practice this requires the delivery catheter and endoscope in combination to be fully rotated to disengage a contraceptive implant device from the delivery catheter in order to deposit the contraceptive implant device into a fallopian tube. This maneuver may be difficult and cumbersome to perform considering that the device must remain axially aligned in the fallopian tube.